I was excited to read this with it being a spin-off of the Mr Mercedes trilogy. It started off slow, but being used to King’s writing style I knew it was going to be worth the wait. The mixture of mystery and horror certainly kept me reading and the idea of never being able to know everything there is about the world. In the words of Bill Hodges, ‘The universe is never ending’. 
Be prepared for graphic descriptions and the crossover of realism with myth & legend.